In each of the following groups of compounds, identify the one with the largest heat of combustion

Question:

In each of the following groups of compounds, identify the one with the largest heat of combustion and the one with the smallest. In which cases can a comparison of heats of combustion be used to assess relative stability?
(a) Cyclopropane, cyclobutane, cyclopentane
(b) cis-1,2-Dimethylcyclopentane, methylcyclohexane, 1,1,2,2-tetramethylcyclopropane
(c)